Struct futures::lock::MappedMutexGuard [−][src]
Expand description
An RAII guard returned by the MutexGuard::map
and MappedMutexGuard::map
methods.
When this structure is dropped (falls out of scope), the lock will be unlocked.
Implementations
pub fn map<V, F>(
this: MappedMutexGuard<'a, T, U>,
f: F
) -> MappedMutexGuard<'a, T, V> where
F: FnOnce(&mut U) -> &mut V,
V: ?Sized,
pub fn map<V, F>(
this: MappedMutexGuard<'a, T, U>,
f: F
) -> MappedMutexGuard<'a, T, V> where
F: FnOnce(&mut U) -> &mut V,
V: ?Sized,
Returns a locked view over a portion of the locked data.
Example
use futures::lock::{MappedMutexGuard, Mutex, MutexGuard}; let data = Mutex::new(Some("value".to_string())); { let locked_str = MutexGuard::map(data.lock().await, |opt| opt.as_mut().unwrap()); let locked_char = MappedMutexGuard::map(locked_str, |s| s.get_mut(0..1).unwrap()); assert_eq!(&*locked_char, "v"); }
Trait Implementations
Auto Trait Implementations
impl<'a, T, U> !RefUnwindSafe for MappedMutexGuard<'a, T, U>
impl<'a, T: ?Sized, U: ?Sized> Unpin for MappedMutexGuard<'a, T, U>
impl<'a, T, U> !UnwindSafe for MappedMutexGuard<'a, T, U>